Meat cooking apparatus and method

ABSTRACT

Cooking apparatus and method for preparing meats to suit individual tastes of different consumers. The meat is subjected to electric current heating to cook the meat and to radiant broiling to char its surface. The cooking current passing through the meat is regulated in response to a comparison of an input corresponding to the desired degree of cooking and an indication of the interior temperature of the meat as it is being cooked. The apparatus and method are particularly suited to handle effectively a variety of individual orders at substantially the same time.

This application is a division of application Ser. No. 42,747, filed May29, 1979, now U.S. Pat. No. 4,244,284.

The present invention relates, in general, to food processing and, inparticular, to an apparatus and method for cooking meat, such as steaks,and the like.

Most consumers of certain meat products, such as steaks, require thatthe meat be cooked to a desired degree of cooking and be served in anappealing manner. The meat should taste good and look good. Satisfyingthese two requirements is especially difficult in restaurants or forlarge gatherings because the chef must cook for so many people at thesame time. Furthermore, from the standpoint of the server of the meatproduct, there should be as little meat moisture loss as possible in themeat preparation to assure serving properly sized portions from properlysized pieces of raw meat.

Many types of cooking equipment are available commercially or have beensuggested in the past. Generally, however, this equipment does notprovide an efficient and effective solution to the concurrent problemsof proper meat preparation and heavy cooking loads. Some have beendesigned for precise cooking but cannot handle effectively a variety ofdifferent orders at substantially the same time. Other have beenarranged for mass cooking but fail to produce meat cooked to theindividual tastes of different consumers. Yet others are designed formass cooking with no concern as to the specific degree of cooking of themeat.

Therefore, it is an object of the present invention to provide a new andimproved apparatus and method for cooking meat.

It is another object of the present invention to provide a meat cookingapparatus and method capable of preparing, in a rapid and efficientmanner, meat products cooked to satisfy a variety of individual tastesunder heavy cooking load conditions.

It is a further object of the present invention to provide a meatcooking apparatus and method which results in a minimum moisture loss ofthe meat as it is prepared.

In accordance with the present invention, a piece of meat is subjectedto electric current heating to cook the meat and radiant broiling tochar its surface. While the meat is being cooked electrically, theinterior temperature of the meat is sensed and compared against a presettemperature which corresponds to the desired degree of cooking of themeat. This comparison is used to regulate the degree of electricalcooking of the meat by the passage of electric current through the meat.A conveying mechanism, which carries the meat through the cooking andbroiling stages without manual handling, renders this operationautomatic.

For a better understanding of the present invention, reference is madeto the following description, taken in conjunction with the accompanyingdrawings in which:

FIG. 1 illustrates the sequence of functions performed by the apparatusand method of the present invention;

FIG. 2 is a perspective view of a preferred embodiment of meat cookingapparatus constructed in accordance with the present invention;

FIG. 3 is a partial side view of the FIG. 2 apparatus with the housingbroken away;

FIG. 4 is a sectional view taken along line 4--4 of FIG. 3;

FIG. 5 is a sectional view taken along line 5--5 of FIG. 4;

FIG. 6 is a time diagram illustrating the movement sequence of theconveying mechanism of the apparatus of the present invention;

FIG. 7 is a time diagram illustrating the manner in which the apparatusof the present invention prepares a plurality of meat products;

FIG. 8 is a block diagram which illustrates one embodiment of thecontrol system of the present invention; and

FIGS. 9a and 9b are circuit diagrams showing the details of thecircuitry of the FIG. 8 block diagram.

FIG. 1 shows the sequence of functions performed by the apparatus andmethod of the present invention. A piece of meat 10, which is to becooked, is loaded into the cooking apparatus at STATION I and moved toSTATION II where the top surface 10a of the meat is subjected to radiantbroiling to soften the meat. The meat then is moved to STATION III whereit is picked up and moved to STATION IV for electric current cooking. AtSTATION IV, electric current is passed through the meat in a regulatedmanner. After electric current cooking, the meat is dropped off atSTATION V with the bottom surface 10b now on top. The meat then is movedto STATION VI and surface 10b, which is now on top, is subjected toradiant broiling to char this surface. Finally, the cooked piece ofmeat, with surface 10b charred, is moved to STATION VII for unloadingfrom the cooking apparatus.

Referring to FIGS. 2, 3, 4 and 5, a piece of meat 10 is loaded into thecooking apparatus of the invention through an opening 12. Although theembodiment illustrated contemplates manual loading, a suitable automaticloading mechanism may be provided to meet the practical requirements ofthe installation. The meat is set on a plurality of rods 14 which formpart of the conveying mechanism for moving the meat through the cookingapparatus. The conveying mechanism will be described in greater detailbelow.

The meat is moved to a position below a first radiant heater 16 whichradiates the top surface 10a of the meat to soften the meat, ifnecessary. A piece of meat taken from a refrigerator has a temperaturein the order of 40° F. As such, the piece of meat, and especially thefatty parts, is hard. In order to cook the piece of meat mosteffectively,the meat should be introduced to the electric currentcooking station in a softened condition, whereby there is enhancedcontact with the cooking electrodes. The details of radiant heater 16will be described with reference to a second radiant heater 30, similarto heater 16, shown most clearly in FIG. 5. Radiant heaters 16 and 30are aligned transversely of the apparatus. Each may include a series ofinfrared lamps 18 which line the interior surfaces of a pair ofreflectors 20 and 21. Preferably, reflectors 20 and 21 are ceramic,self-cleaning reflectors which reflect the light emanating from lamps 18onto the meat. The arrows associated with reflectors 20 and 21 indicatethat the reflectors and lamps 18 may be swung into and out of positionfor cleaning and maintenance purposes. Lamps 18 may be of the quartzhalide type, collectively capable of developing a temperature ofapproximately 1800° F. at the surface of the meat from a power output ofabout 10,000 watts for approximately 30 seconds. This infrared radiationwill soften the meat at STATION II and produce an appearance comparableto charcoal broiling on surface 10b at STATION VI. The degree ofsoftening is variable and may be controlled by providing a range ofpower outputs from 3000 watts to 10,000 watts over a time period of zeroto 60 seconds depending on the softness or hardness of the meat as it isto be introduced into the cooking apparatus. The degree of charring isvariable and may be controlled to produce a range of effectssatisfactory to the average consumer by providing a range of poweroutputs from 3000 watts to 10,000 watts over a time period of 15 secondsto 60 seconds. Preferably, the degree of charring is set by fixing thepower output and broiling time to produce the same satisfactory effectfor all pieces of meat to be prepared. However, with suitablemodifications, various charring effecting may be produced to satisfy theindividual desires of consumers.

After surface 10a is broiled, the meat is moved by the conveyingmechanism to a position where it is engaged by a pair of electrodes 22and 24 for electric current cooking of the meat. These electrodes areformed by a plurality of electrode fingers 22a and 24a, respectively,which are made from a carbon material Carbon has been found to have thenecessary characteristics which provide good contact with the meat forproper electric current cooking without sticking to the meat aftercooking is completed, whereby the meat is easily released from theelectrode fingers with no adverse effect on the appearance of the meat.

The electrode fingers are disposed perpendicular to the direction ofmovement of rods 14 and a similar set of rods 26 on the opposite side ofthe cooking apparatus. Fingers 22a and 24a are shaped and sized topermit fingers 22a to pass between rods 14 and fingers 24a to passbetween rods 26 as the electrodes are moved between rods 14 and 26.

Normally, electrodes 22 and 24 are biased toward each other by suitablemeans, such as a spring. As the electrodes move into registration withrods 14, fingers 22a of electrode 22 pass between rods 14 to a positionbelow these rods, while electrode 24 engages a detent 56 which preventsfurther movement of this electrode causing a separation of theelectrodes. With fingers 22a below rods 14 and fingers 24a above rods14, there is adequate clearance for rods 14 to move between theelectrodes and deliver a piece of meat to this location between theelectrodes.

After the meat has been delivered to this location, the electrodes aremoved away from rods 14 and brought together to tightly engage the meat.The meat is carried to the cooking location by the electrodes.

Electric current is passed through the meat between electrode fingers22a and 24a to cook the meat. In order to prevent a short-circuit, thecooking current is not applied until electrode fingers 22a clear rods14. Preferably, the meat is cooked with the electrodes in a fixedvertical position, since such an arrangement simplifies the applicationof the current to the electrodes. The nature of the meat and the desireddegree of cooking determine the amount of electric current heating whichis required. With a fixed level of current, the time of cooking isvaried to achieve the desired degree of cooking. Among the factors whichmay affect the required duration of cooking for a desired degree ofdoneness are the type and thickness of the meat, its moisture content,and the salt content.

Fingers 22a of electrode 22 and fingers 24a of electrode 24 are arrangedto clamp a piece of meat tightly as the electrode heads are moved awayfrom rods 14. As best seen in FIGS. 3 and 5, the electrode fingers aremounted for quadrature pivotal movement about two transverse axes topermit the electrodes to conform to thickness variations in the meat.Electrode fingers 24a pivot about a pin 25 (FIG. 3), while electrodefingers 22a pivot about pin 27 perpendicular to pin 25 (FIG. 5). Asstated previously, the broiling of the meat by radiant heater 16enhances the effectiveness of the electric current cooking in that themeat is delivered to electrodes 22 and 24 in a softened condition,whereby better contact between the electrode fingers and the meatsurface is achieved.

A thermocouple 28, mounted on electrode 22, in electrical and thermalisolation from the electrode, penetrates bottom surface 10b of the meatas electrode fingers 22a engages this surface. The thermocouple sensesthe interior temperature of the meat as it is being cooked and developsa sensing signal representative of this temperature. Because of thedirect correlation between the interior temperature of the meat and thedegree of cooking of the meat, the thermocouple sensing signal isrepresentative of the degree of cooking. This sensing signal is comparedagainst a preset temperature input signal corresponding to the degree towhich the particular piece of meat is to be cooked and the result ofthis comparison is used to control the duration of the electric currentpassing through the meat. In developing the setting for the presettemperature input signal, it has been found that for steaks, thistemperature is between 120° F. and 160° F. for a "rare" cooking; 140° F.and 180° F. for a "medium" cooking; and 160° F. and 200° F. for a"well-done" cooking.

After the piece of meat has been cooked, the conveying mechanism movesthe electrodes, carrying the meat, to a position where the meat isdeposited on rods 26. The arrangement is such that the bottom surface10b of the meat now is on top. As the electrode fingers move intoregistration with rods 26, fingers 24a of electrode 24 pass between rods26 to a position below these rods, while electrode 22 engages a detent,similar to detent 56, which prevents further movement of this electrodecausing a separation of the electrodes as the meat is deposited on rods26. With fingers 24a below rods 26 and fingers 22a above rods 26, thereis adequate clearance for rods 26 to move between the electrode fingersand carry away a piece of meat from this location between theelectrodes. The meat then is moved by the conveying mechansim to aposition below the second radiant heater 30 which broils bottom surface10b of the meat to char this surface and develop the desired appearance.

After surface 10b is broiled, the meat is moved by the conveyingmechanism to a position where it may be removed from the cookingapparatus through an opening 31. Unload opening 31 and load opening 12are aligned transversely of the apparatus. As with load opening 12, asuitable automatic removal mechanism may be provided instead of themanual removal capability illustrated.

The conveying mechanism which moves the meat through the cookingapparatus includes an input conveyor 32 and an output conveyor 34. Inputconveyor 32 and output conveyor 34 are disposed parallel to each otherat opposite sides of the apparatus. They are located at the same heightand arranged to move in opposite directions. Since the two conveyorspreferably are similar, only the details of input conveyor 32 will bedescribed. Rods 14 are secured in a cantilevered manner at their outerends to an endless chain 36 and to a second endless chain (not shown) ata point inward of the ends, for example, one-third of the rod lengthfrom the ends. The chains are driven longitudinally of the cookingapparatus by drums 38, 40 and 42 each having drive surfaces shaped toreceive rods 14. The rods are supported transversely and are preventedfrom pivoting downwardly which would tend to occur especially when theycarry pieces of meat by their attachment to the two chains and by anangle, such as the one shown in FIG. 5 as part of the output conveyorand identified by reference numeral 44. Angle 44 extends longitudinallyof the apparatus, below the rods, and is inward of the inner chain. Inthis way, rods 14 are maintained horizontal and perpendicular to theirmovement as chain 36 is driven.

Electrodes 22 and 24 are positioned between input conveyor 32 and outputconveyor 34 at a distance longitudinally of the apparatus from radiantheaters 16 and 30 equal to the longitudinal distance between load andunload openings 12 and 31 and the radiant heaters. The electrodes aremounted on a shaft 47 for pivotal movement between the conveyors. Asthis shaft is driven, the electrodes swing through 180° arcs extendingbetween the conveyors and perpendicular to the disposition of theconveyors.

Input conveyor 32, output conveyor 34 and electrodes 22 and 24 aredriven by a mechanical power transmission system 50 powered by anelectric motor 48 through an electro-mechanical clutch/brake mechanism52. Electric motor 48 is arranged to run continuously with its outputcoupled to mechanical power transmission system 50 at selected times bythe control of clutch/brake mechanism 52. Movements of input conveyor32, output conveyor 34 and electrodes 22 and 24 are started by actuationof control switches and stopped by an electro-mechanical timing device53. The actuation of the control switches and the action ofelectro-mechanical timeing device 53 causes engagement and disengagementof the clutch and brake of clutch/brake mechanism 52 to initiate andstop movements of input conveyor 32, output conveyor 34 and electrodes22 and 24.

Mechanical power transmission system 50 may be of any suitable designwhich produces controlled movements of input conveyor 32 and outputconveyor 34, whereby these two conveyors move in opposite directions,over fixed distances, intermittently at different times. Although notshown, mechanical power transmission system 50 may include a single-pinGeneva gear mechanism in which two diametrically opposed Geneva starwheels are driven to develop controlled rotational movements at theappropriate times. These rotational movements are coupled throughappropriate gearing to input conveyor 32 and output conveyor 34 toeffect fixed movements of the conveyors equal to the longitudinaldistance between load and unload openings 12 and 31 and radiant heaters16 and 30. This distance is equal to the longitudinal distance betweenradiant heaters 16 and 30 and electrodes 22 and 24.

Mechanical power transmission system 50 also provides the drive forshaft 47 which transfers electrodes 22 and 24 between input conveyor 32and output conveyor 34.

The movements of input conveyor 32, output conveyor 34 and electrodes 22and 24 are controlled precisely so that the timing of these movementsand the positioning of these components bring rods 14 to rest at aposition which permits fingers 22a of electrode 22 to pass through theplane of movement of rods 14 and bring rods to rest at a position whichpermits fingers 24a of electrode 24 to pass through the plane ofmovements of rods 26. FIG. 6 illustrates the timing sequence of themovements of input conveyor 32, output conveyor 34 and electrodes 22 and24 and the energization of radiant heaters 16 and 30 and electrodes 22and 24. As depicted, an operating cycle of the cooking apparatusincludes a Movement Period, a Cooking Period, and two Broiling Periodswhich overlap the Movement Period and the Cooking Period. Because theBroiling Periods typically are somewhat longer than the Movement Period,the time period during which the Broiling Periods and the Cooking Periodoverlap is shown with a break. For example, a typical Movement Periodmay be in the order of 10 seconds, while the Broiling Periods may be inthe order of 40 seconds.

In FIG. 6, the cycle of operation starts with electrodes 22 and 24 inthe cooking position, with no meat between the electrodes. Next,electrodes 22 and 24 swing together 90° clockwise, when viewed in FIG.5, to a position in which fingers 24a of electrode 24 have passedbetween rods 26 and are below these rods, while fingers 22a of electrode22 remain above rods 26. This pivotal movement of the electrodes occurswhile output conveyor 34 is stationary. Next, output conveyor 34 ismoved a fixed amount, namely the distance between two STATIONS (e.g.radiant heater 30 and opening 31) on the output side of the apparatus.After output conveyor 34 has moved this prescribed amount and comes torest, electrodes 22 and 24 swing together counterclockwise 180° C. to aposition in which fingers 22a of electrode 22 have passed between rods14 and are below these rods, while fingers 24a of electrode 24 remainabove rods 14. This rotation of the electrodes occurs while inputconveyor 32 is stationary and before a piece of meat has been deliveredby rods 14 to this location, namely STATION III (PICK-UP). Afterelectrodes 22 and 24 are positioned at STATION III and with theelectrode fingers separated, input conveyor 32 is moved to deliver apiece of meat 10 from STATION II (TOP SURFACE RADIANT BROILING) toSTATION III. After input conveyor 32 has delivered a piece of meat toSTATION III, input conveyor 32 is stationary, electrodes 22 and 24 cometogether as they swing clockwise 90° carrying the piece of meat awayfrom STATION III to STATION IV for electric current cooking. Thiscompletes the Movement Period and starts the Cooking Period.

After the meat has been cooked, the Movement Period or the cycle isrepeated. Specifically, electrodes 22 and 24, carrying the cooked pieceof meat, swing 90° clockwise, with fingers 24a of electrode 24 passingbetween rods 26 of output conveyor 32. Electrodes 22 and 24 separate todeposit the meat on rods 26. Output conveyor 34 then is moved andcarries the meat away from STATION V (DROP-OFF) to STATION VI forradiant broiling of the bottom surface of the meat which is now on top.After output conveyor 34 comes to rest electrodes 22 and 24 swingtogether counterclockwise 180° to STATION III (PICK-UP) and come intoposition ready for the delivery of another piece of meat by inputconveyor 32. In the meantime, with the meat at STATION VI, radiantheater 30 is energized and the meat is broiled. Radiant heater 30 isenergized shortly before the meat is delivered to STATION VI to allowthe heater to develop full intensity before conveyor 34 comes to a stopwith the meat below the heater. Radiant heater 16 is operated in asimilar manner. This heater is energized shortly before the meat isdelivered to STATION II to allow the heater to develop full intensitybefore conveyor 32 comes to a stop with the meat below the heater.

FIG. 7 is a time diagram which illustrates the manner in which theapparatus of the present invention prepares a plurality of meatproducts. The horizontal axis of FIG. 7 represents time and indicatesthe Movement Periods, the Broiling Periods and Cooking Periods, whilethe vertical axis indicates the particular STATIONS at which differentplaces of meat are located at any particular time. A first piece of meat(NO. 1), which is to be "rare" cooked, is loaded into the cookingapparatus at STATION I. Meat No. 1 remains at STATION I for a designatedperiod of time while the first three movements, shown in FIG. 6, takeplace. When input conveyor 32 moves, meat No. 1 moves from STATION I toSTATION II. A second piece of meat (No. 2), which is to be "medium"cooked, now may be loaded into the cooking apparatus. During the firstMovement Period, the first Broiling Period begins. Upon completion ofthe first Movement Period, the first Cooking Period begins. While meatNo. 1 receives the top surface broiling at STATION II, meat No. 2remains at load STATION I.

After the first Broiling Period and first Cooking Period are completed,a second Movement Period begins and after a designated period of time,input conveyor 32 moves carrying meat No. 1 from STATION II to STATIONIII and meat No. 2 from STATION I to STATION II. A third piece of meat(No. 3), which is to be "well-done" cooked, now may be loaded into thecooking apparatus. Meat No. 1 is in position to be picked up at STATIONIII, meat No. 2 is at STATION II receiving top surface broiling becausethe second Broiling Period has started, and meat No. 3 is at loadSTATION I. With input conveyor 32 stationary, the electrode heads pickmeat No. 1 off of conveyor 32 and deliver meat No. 1 to STATION IV. Uponcompletion of the second Movement Period, the second Cooking Periodbegins. Meat No. 1 receives electric current cooking at STATION IV, meatNo. 2 receives the top surface broiling at STATION II and meat No. 3remains at load STATION I.

After the second Broiling Period and second Cooking Period arecompleted, a third Movement Period begins. The electrodes swing 90°clockwise to drop meat No. 1 on output conveyor 34 which is stationary.Next, output conveyor 34 carries meat No. 1 from STATION V to STATIONVI. Upon delivery of meat No. 1 to STATION VI, output conveyor 34 stops.With output conveyor 34 stationary and input conveyor 32 alsostationary, the electrodes swing through a 180° counterclockwise arc toposition the electrodes at STATION III ready to receive meat No. 2.Next, input conveyor 32 moves carrying meat No. 2 from STATION II toSTATION III and meat No. 3 from STATION I to STATION II. A fourth pieceof meat (No. 4), which is to be "medium" cooked, now may be loaded intothe cooking apparatus. Meat No. 1 is at STATION VI receiving bottomsurface broiling because the third Broiling Period has started, meat No.2 is in position to be picked up at STATION III, meat No. 3 is atSTATION II receiving top surface broiling because the third BroilingPeriod has started, and meat No. 4 is at load STATION I. With inputconveyor 32 stationary, the electrodes pick meat No. 2 off of conveyor32 and deliver meat No. 2 to STATION IV. Upon completion of the thirdMovement Period, the third Cooking Period begins. Meat No. 1 receivesbottom surface broiling at STATION VI, meat No. 2 receives electriccurrent cooking at STATION IV, meat No. 3 receives top surface broilingat STATION II, and meat No. 4 remains at load STATION I.

After the third Broiling Period and third Cooking Period are completed,a fourth Movement Period begins. The electrodes swing 90° clockwise todrop meat No. 2 on output conveyor 34 which is stationary. Next, outputconveyor 34 carries meat No. 1 from STATION VI to STATION VII and meatNo. 2 from STATION V to STATION VI. Upon delivery of meat No. 1 toSTATION VII and meat No. 2 to STATION VI, output conveyor 34 stops. Withoutput conveyor 34 stationary and input conveyor 32 also stationary, theelectrodes swing through a 180° counterclockwise arc to position theelectrodes at STATION III ready to receive meat No. 3. Next, inputconveyor 32 moves carrying meat No. 3 from STATION II to STATION III andmeat No. 4 from STATION I to STATION II. A fifth piece of meat (No. 5)now may be loaded into the cooking apparatus. Meat No. 1 is in positionto be unloaded at STATION VII, meat No. 2 is at STATION VI receivingbottom surface broiling because the fourth Broiling Period has started,meat No. 3 is in position to be picked up at STATION III, meat No. 4 isat STATION II receiving top surface broiling because the fourth BroilingPeriod has started, and meat No. 5 is at load STATION I. With inputconveyor 32 stationary, the electrodes pick meat No. 3 off conveyor 32and deliver meat No. 3 to STATION IV. Upon completion of the fourthMovement Period, the fourth Cooking Period begins. Meat No. 2 receivesbottom surface broiling at STATION VI, meat No. 3 receives electriccurrent cooking at STATION IV, and meat No. 4 receives top surfacebroiling at STATION II. Meat No. 1 remains at unload STATION VII andmeat No. 5 remains at load STATION I.

The cycling just described repeats to move the pieces of meat loadedinto the cooking apparatus through the broiling and cooking STATIONS. Ifadditional pieces of meat are not loaded into the cooking apparatus, theapparatus is cycled, in the manner described, until the last piece ofmeat is delivered at unload STATION VII.

Referring to FIG. 2, the operations previously described are regulatedand initiated from two control panels. The first, designated byreference numeral 62, is a chef's control panel, through which certainof the operating conditions are set by a chef. For example, the poweroutput and duration of radiation from radiant heaters 16 and 30 arepreset by the chef to develop the level of broiling which produces thedesired softening of the meat and the desired appearance of the meat.The chef also presets the various temperatures to which different piecesof meat should be cooked to achieve the desired degrees of cooking. Inorder to prevent unauthorized changes to these settings, chef's controlpanel 62, preferably is covered.

With the major operating conditions established and set into the cookingapparatus, individual pieces of meat may be prepared by unskilledoperators who simply load pieces of meat and push various buttonsconsistent with the orders for the meat preparation. These buttons arelocted at an operator's control panel, designated by reference numeral64. Thus, the operator merely makes the selection as to the degree ofcooking desired and can start or stop the apparatus as needed. Althoughthe embodiment of the cooking apparatus disclosed herein includes onlythree degrees of cooking, namely "rare", "medium", and "well-done", itwill be understood that in practice, additional cooking degrees, such as"medium-rare" and "medium-well" will be desirable, andthat such addedflexibility is easily incorporated in the apparatus.

In order to keep track of the degree of cooking of various pieces ofmeat being prepared by the apparatus at the same time, a series oflights 66 are provided adjacent unload opening 31. As a cooked piece ofmeat reaches this opening, the appropriate light 66, corresponding tothe degree to which the meat has been cooked, lights up, so that theoperator may identify the meats with flags, taken from recesses 70,which indicate the cooking degree.

FIG. 8 is a block diagram illustrating one embodiment of a controlsystem for the cooking apparatus of the present invention. Prior tousing the cooking apparatus to prepare meat products, the chef setsvarious operating conditions by adjustments of dials located at chef'scontrol panel 62. In particular, the power output and duration ofradiation from radiant heaters 16 and 30 are set to develop the level ofbroiling required to produce the desired softening of the meat and thedesired appearance of the meat. This setting control, represented byradiant heaters setting 100, is supplied to radiant heaters 16 and 30.The chef also presets the various temperatures to which different piecesof meat should be cooked to achieve the desired degrees of cooking,namely "rare", "medium" and "well-done". This settingcontrol,represented by electric cook setting 102, is supplied to makeselection circuit 106 located at operator's control panel 64.

Electric motor 48 is started by closing a start/stop switch 104 locatedat operator's control panel 64. This action readies the cookingapparatus for the cooking process and conditions make selection circuit106 to receive a setting for the cooking degree selection. Afther theoperator has loaded a piece of meat onto the input conveyor, he actuatesthe make selection circuit 106 by selecting the setting for the desiredcooking degree which has been established by electric cook setting 102.

The output of make selection circuit 106 is supplied to clutch/brake 52to disengage the brake and engage the clutch. The output of makeselection circuit 106 also is supplied to electro-mechanical (E/M)timing device 53 to initiate the timing function of this unit. Theoutput of make selection circuit 106 is also supplied to anelectro-mechanical (E/M) memory 108 which stores a signal representativeof the desired degree of cooking for the piece of meat loaded into theapparatus. Memory 108 may be a conventional memory drum in whichinformation is stored at one or more discrete locations, so that as thedrum rotates, in synchronism with mechanical transmission system 50, thestored information may be read from the drum signals developed tocontrol various components of the control system at the appropriatetimes. With the clutch of clutch/brake 52 engaged, mechanical powertransmission system 50 is driven to cycle electrode transfer 47, outputconveyor 34 and input conveyor 32 in the manner illustrated in FIG. 6.At the same time, mechanical power transmission system 50 driveselectro-mechanical memory 108 in synchronism.

After electro-mechanical timing device 53 has run down, the clutch ofclutch/brake 52 is disengaged and the brake of clutch/brake 52 isengaged. Electro-mechanical timing device 53 also initiates the Broilingand Cooking Periods of the apparatus by supplying signals to cookingelectrode heads 22 and 24, radiant heater 16 and radiant heater 30. p Atthe completion of the Cooking Period, another cycle of operation may beinitiated in one of two ways depending upon whether a second piece ofmeat is loaded into the unit. In the absence of a second piece of meat,the operator pushes an advance button 110, located at the operatorcontrol panel 64, and the same cycle, previously described, is repeated.If a second piece of meat is loaded into the apparatus, the operatoragain selects the cooking degree desired at the make selection circuit106 and initiates the cycle previously described.

Whether by actuation of make selection circuit 106 or advance button110, the piece of meat is delivered to cooking electrodes 22 and 24 andcarried by the electrodes into the cooking position. As the apparatus iscycled, with the piece of meat passing through the apparatus,electro-mechanical memory 108 also moves in synchronism, so that whenelectric current cooking of the piece of meat is to take place, thememory supplies to a comparator 112 the stored signal representative ofthe desired degree of cooking. As electric current is passed betweenelectrode fingers 22a and 24a through the meat, thermocouple 28 sensesthe interior temperature of the meat. Comparator 112 controls theduration of time over which electric current is passed through the meatin response to a comparison of the thermocouple signal and the signalfrom electro-mechanical memory 108. When the two signals are equal thecomparator turns off the electric current.

After the Cooking Period is over, the cooking apparatus is again cycleseither by actuation of make selection circuit 106, if another piece ofmeat is to be cooked, or by advance button 110 the necessary number oftimes until the piece of meat is delivered to the unload location.Electro-mechanical memory 108, moving in synchronism with the variouscomponents of the conveying mechanism, supplies a signal to unloadindicator 66 to indicate the degree of cooking of the meat. Theoperator, with the benefit of this indication, identifies the meat witha suitable flag representing this degree of cooking.

In the embodiment of the control system illustrated in FIG. 8, radiantheaters 16 and 30 and electrodes 22 and 24 are activated during eachBroiling Period and each Cooking Period regardless of the presence of apiece of meat at these locations. In order to conserve energy andminimize the heating of the cooking apparatus, additional controlconnections are effected through electro-mechanical memory 108 toseparately control the operations of radiant heaters 16 and 30 andelectrodes 22 and 24, so that these components are powered only when apiece of meat is at any of the three locations.

FIGS. 9a and 9b show the circuit details of the FIG. 8 control system.Only selected portions of the circuitry shown in FIGS. 9a and 9b need tobe described to provide an adequate understanding of the operation ofthe control system.

The main power is supplied from a 240 volt, 60 cycle, three phasesource. This power is supplied through a power switch 214 and threefuses 210, 211 and 212.

The amount of power supplied to radiant heaters 16 and 30 is controlledby triacs 213 and 231, respectively, which are operated asphase-controlled switches and controlled by standard triac phase controlcircuits 215 and 233, respectively. A pair of rheostats 217 and 235,located at chef's control panel 62, are set by the chef to establish theparameters of triac phase control circuits 215 and 233, respectively,thereby determining the amount of power supplied to radiant heaters 16and 30, respectively. The time over which power is supplied to radiantheaters 16 and 30 is established by the chef by setting a pair of timers282 and 313, also located at chef's control panel 62. These two timersare commercially available, motor driven timers, such as Eagle SignalCycl-Flex Timer HP 52A6.

The power supplied to electrodes 22 and 24 is controlled by a triac 221which is operated as a phase-controlled switch and controlled by astandard triac phase control circuit 223. A rheostat 225, located atchef's control panel 62, is set by the chef to establish the parametersof triac phase control circuit 223 and, thereby, establish the power toelectrodes 22 and 24. The maximum time over which power is supplied toelectrodes 22 and 24 is established by the chef by setting a timer 293,also located at chef's control panel 62. This timer is set beyond thetime required to cook a piece of meat "well-done". Timer 293 is similarin construction and operation to timers 282 and 313.

The chef also sets three potentiometers 301, 303 and 305, located at thechef's control panel 62, for the preset electric current cookingconditions corresponding to "rare", "medium" and "well-done". Thesettings of these potentiometers establish voltage levels which areselectively supplied to a temperature control circuit 295 depending uponthe desired degree of cooking for a given piece of meat.

Actuation of start/switch 104 energizes a relay 251 which closes relaycontacts 251a, 251b, 251c and 251d, thereby connecting motor 48 to themain power supply. Actuation of start switch 104 also energizes a relay254 which closes relay contacts 254a and 254b, to connect various othercontrol components, such as relays, to the secondaries of transformers237 and 239. Transformer 237 is part of a 120 volt circuit andtransformer 239 is part of a 24 volt circuit. Those two circuits powerthe control components as they are selectively actuated to effect thedesired operations.

When the operator presses, for example, "medium" switch 106b of makeselection circuit 106 a number of connections are effected. Switch blade106g closes to energize "medium" light 216 at the operator's controlpanel 64. Switch blade 106h closes to energize relay 247 which opensrelay contact 247a, thereby, turning off make selection light 229 at theoperator's control panel 64. The closing of switch blade 106h alsoenergizes relay 321 which closes relay contact 321a, thereby energizingclutch 52a of clutch/brake 52. When clutch 52a is energized, cams 318,382, 312, 316 and 319, mechanically ganged together, rotate a prescribedamount. Cam 318 closes a cam switch 320 which provides holding contactfor relays 247 and 321.

Pressing "medium" switch 106b also closes switch blade 106i which islocated within electro-mechanical memory 108. When this switch blade isclosed, power is applied through a cam switch 281, which has been closedby the rotation of cam 283, to timer 282 for controlling radiant heater16. Cam switch 281 is actuated by cam 283 only during the time thatpower may be supplied to radiant heater 16 for top surface broiling.While timer 282 runs down, power is supplied to radiant heater 16.

Pressing "medium" switch 106b also closes switch blade 106j to energizerelay 286 which closes relay contacts 286a, 286b and 286c. The closingof relay contact 286a causes power to be applied through a cam switch315, which has been closed by the rotation of cam 316, to timer 313 forcontrolling radiant heater 30. Cam switch 315 is actuated by cam 316only during the time that power may be supplied to radiant heater 30 forbottom surface broiling. The closing of relay contact 286a also causespower to be applied through a cam switch 311, which has been closed bythe rotation of cam 312, to timer 293 for controlling the current flowbetween electrode fingers 22a and 24a. Cam switch 311 is actuated by cam312 only during the time that power may be supplied to electrode fingers22a and 24a. The closing of relay contact 286b causes a relay 306 to beenergized which closes relay contact 306a. This action selects theproper preset potentiometer 303, corresponding to "medium" cooking. Theclosing of relay contact 286c energized "medium" light 66b of unloadindicator 66.

While timers 282 and 313 are running down, relays 242 and 244 areenergized which closes relay contacts 242a, 242b and 244a, 244b,respectively, to supply power to radiant heaters 16 and 30 respectively.This is so because relay contacts 340a and 342a, in series with relays242 and 244, respectively, are closed as a result of timers 282 and 313being on. While timer 293 is running down, a relay 291 is energizedwhich closes relay contacts 291a and 291b to supply power to electrodes22 and 24. This is so because relay contact 344a, in series with relay291, is closed as a result of timer 293 being on. Thus, power issupplied to radiant heaters 16 and 30 and electrodes 22 and 24 only ifthe associated relay contacts 340a, 342a and 344a are closed to permitrelays 242, 244 and 291 to be energized. Relay contacts 340a, 342a and344a are selectively closed only if the associated timers 282, 313 and293 are running. In this way, power is only applied to radiant heaters16 and 30 and electrodes 22 and 24 when needed to broil or cook a pieceof meat at these locations as indicated by the activation of timers 282,313 and 293.

The signal from thermocouple 28 and the output of potentiometer 303 aresupplied to temperature control circuit 295 and compared. When thethermocouple signal reaches the preset level established bypotentiometer 303, temperature control circuit 295 causes a relaycontact 294a to open, thereby de-energizing relay 291. This, in turn,opens relay contacts 291a and 291b to stop the current flow betweenelectrode fingers 22a and 24a. In no event will the current flow betweenelectrode fingers 22a and 24a continue after the run down of timer 293,since this timer, at the completion of run down, also will de-energizerelay 291. The running time of time 293 is set for a period longer thanthat required for "well-done" cooking.

At the completion of a Movement Period, cam 318 permits cam switch 320to open. This causes relays 247 and 321 to be de-energized, therebyde-activating clutch 52a.

If instead of cooking a piece of meat "medium", the meat is to be cooked"well-done", the same operation, just described, takes place, exceptthat an indicator light 66c, corresponding to the "well-done" cookingcondition is energized and the output of potentiometer 305, preset for"well-done" cooking, is supplied to temperature control circuit 295.

For a "rare" cooking, the action again is similar to that describedexcept that a time delay circuit 331 comes into operation. This timedelay circuit is provided to delay the start of the meat temperaturesensing by thermocouple 28 for a prescribed time, approximately threeseconds, after the Cooking Period has begun. This delay is introducedbecause it has been found that the ambient temperature in the cookingarea may rise above the preset "rare" temperature setting so that, undersuch conditions, it is necessary to insert the thermocouple into thepiece of meat before activating temperature control circuit 295.

When a second piece of meat is not introduced into the cookingapparatus, pushing advance button 333 causes the circuit to operate inthe same manner as described above except that power to radiant heater16 is not applied.

The cooking apparatus of the present invention also may include a troughsystem for flowing cold water beneath the path of meat movement throughthe apparatus. The flowing cold water serves a number of purposes.First, meat drippings are carried away by the water flow. Second, thecold water cools the apparatus. Third, the water surface is highlyreflective and enhances the effectiveness of the radiant heaters.Fourth, the water increases the moisture within the apparatus andimproves the cooking quality of the meat.

The cold water is introduced into a pair of troughs located beneath theupper paths of travel of rods 14 and 26. Only one such trough 72,associated with output conveyor 34, is shown in FIG. 5. The waterflowing through these two troughs flows into a tank 70 and is dischargedthrough outlet 92. In this way, meat drippings are removed from thecooking apparatus.

The cooking apparatus includes a second pair of troughs associated withthe input and output conveyors. Only one such trough 90, associated withinput conveyor 32, is shown in FIG. 5. Hot water, at a temperature ofapproximately 180° F., is introduced by suitable means to these troughs.As the rods 14 and 26 and their associated drive chains pass throughthis hot water, the rods and chains are cleaned. This water isdischarged through outlets 76 and 78.

It is preferable, from the standpoint of energy conservation, to enclosethe various components of the apparatus within a housing. By keeping thebroiling and cooking areas warm and humid, the meat preparation usesless energy and produces a better product. In order to afford access tothe interior of the apparatus, a pair of doors 80 and 82 are provided.When elevated, these doors, may be held in position by guide rods 84 and86, respectively.

Meat prepared by the embodiment of the cooking apparatus just describedchars only one surface, namely the top surface 10b of the meat as it iscarried by output conveyor 34. If it is desired to char both the top andbottom surfaces, a third radiant heater 88, shown in dotted lines inFIG. 3, may be positioned below rods 26 at STATION VI. This heater, inalignment with radiant heater 30, would be energized whenever heater 30is energized, so as to produce a piece of meat charred on both top andbottom surfaces.

From the foregoing description, it is seen that the present inventionprovides an efficient and effective apparatus and method for preparingmeats in large quantities with each piece of meat being pleasing to theconsumer. For the embodiment of the invention described, an unskilledoperator can prepare pieces of meat which satisfy the concurrentrequirements of proper doneness and appealing appearance at the rate ofapproximately seventy pieces per hour, although much higher rates arepossible with suitable modifications to the apparatus. Also, it has beenfound that meats prepared according to the present invention undergominimum moisture less. This permits preparing properly sized portionsfrom properly sized pieces of raw meat.

While the foregoing description discloses a preferred embodiment of thepresent invention, it will be obvious to one skilled in the art thatvarious modifications may be made which are within the intended scope ofthe invention as set forth in the appended claims.

What is claimed is:
 1. A conveying mechanism for transporting an articlecomprising:a first endless conveyor for carrying said article, saidfirst conveyor having a first plurality of cantilevered rods disposedperpendicular to the movement of said first conveyor and secured attheir outer ends to a first chain; a second endless conveyor forcarrying said article, said second conveyor having a second plurality ofcantilevered rods disposed perpendicular to the movement of said secondconveyor and secured at their outer ends to a second chain; first andsecond transfer members each having a plurality of fingers disposedperpendicular to the movements of said conveyors and sized and spacedfrom each other to pass between said cantilevered rods, said first andsecond transfer members adapted to engage opposite surfaces of saidarticle; means for mounting said first and second transfer membersbetween said conveyors for pivotal movement between said conveyorsthrough an arc perpendicular to the movements of said conveyors; andmeans for driving said conveyors and said transfer members at prescribedtimes.
 2. A conveying mechanism according to claim 1 wherein the arcthrough which the transfer members move extends from one position atwhich said transfer members are on opposite sides of the plane ofmovement of said first plurality of rods to a second position at whichsaid transfer members are on opposite sides of the plane of movement ofsaid second plurality of rods.
 3. A conveying mechanism according toclaim 2 wherein the conveyors are parallel to each other and the twopluralities of rods move in the same plane.
 4. A conveying mechanismaccording to claim 3 wherein the conveyors move in opposite directions.5. A conveying mechanism according to claim 2 further including firstmeans for stopping pivotal movement of the second transfer member as thefirst transfer member moves to a position on the opposite side of theplane of movement of the first plurality of rods and second means forstopping pivotal movement of the first transfer member as the secondtransfer member moves to a position on the opposite side of the plane ofmovement of the second plurality of rods.